| 摘要 |
PROBLEM TO BE SOLVED: To solve the problem, wherein in conventional compression technologies, for example, since a load of conversion processing is high, when representing a node with a declination, high arithmetic-operation throughput is required at a device side, and for data compression utilizing a difference, for example, if respective values of numerical data are approximate to one another, compression efficiency can be maintained high, but among data with considerably different values, it is conversely possible to increase a data amount, and further, when performing processing to determine whether or not the data amount can be reduced in order to avoid increase, and as a result, a long processing time is required. SOLUTION: A coordinate compressor includes a function for receiving coordinate sets on a map, which mainly comprise adjacent points in many cases and in which numbers of an upper digit are approximate, and for calculating the difference relating to the coordinate sets to compress the data amount. COPYRIGHT: (C)2011,JPO&INPIT |
